Recently, a network environment has emerged where a number of base stations forming cells of different sizes are disposed in the same area in LTE network.
In such network environment, various kinds of small base stations having smaller coverage (cell) than typical macro base stations are disposed/coexist, such that various kinds of base stations form macro cells and small cells in overlapping area to provide communications service for users.
In such network environment where macro cells and small cells coexist, a plurality of small cells may be included in a macro cell.
If macro base stations and small base stations employ frequency division duplex (FDD) in such network environment, the macro base stations and the small base stations use a common frequency band for uplink/downlink transmission. As a result, interference takes place between uplink signals and between downlink signals.
Specifically, interference in downlink transmission takes place due to a downlink signal transmitted from another base station than the base station to which a terminal is connected. In addition, interference in uplink transmission takes place due to an uplink signal transmitted from another terminal connected to another base station than the base station to which the terminal is connected.
Signals working as such interference cannot be understood by a receiving end and thus decrease signal to the interference and noise ratio when they are introduced into a signal to be received. As a result, the quality of the communications service is degraded.
In view of the above, the exemplary embodiments of the present disclosure propose an approach to efficiently remove call interference between base stations employing FDD.